The Numbers

1. Energy Use Reduction

  • Multifamily residential buildings:

    • Typical DERs reduce site energy consumption by 20–30%.

    • In more aggressive retrofits, reductions of 40–60% are achievable.
      (DOE, NREL, and Urban Institute studies)

  • Deep retrofits—including insulation, air sealing, heat pumps—can cut energy use by 58–79%, though these are typically single-family and not cost-focused. ACEEE

2. Increase Valuation of Property: 

  • A meta-analysis of green-certified and high-performance retrofitted buildings found valuation uplifts in the 10–15% range (primarily from higher NOI due to reduced operating costs and lower vacancy). Gholamzadehmir, Pandolfi, Del Pero, Leonforte, Sdino (MDPI, 2025)

  • Some case studies show even higher gains — for example, Castle Square Apartments in Boston saw around a 15–20% increase in valuation after its retrofit.

In more aggressive retrofits,

reductions of 40–60% are

achievable.                             

3. Reduction in Insurance Premiums 

  • For multifamily building owners, a well-designed deep energy retrofit can realistically yield 5–10% savings on insurance premiums. (Urban Land Institute (ULI) & Rocky Mountain Institute (RMI)

  • If the retrofit includes risk-mitigating features (e.g., resilience upgrades, certified green standards), savings could be higher—potentially reaching 15–25%, depending on insurer programs and regional standards.( Sustainable Certification Incentives Insurers such as Zurich, FM Global, and AIG)

  • Some programs—like FORTIFIED—offer significantly larger discounts in wind-prone regions (20–55%), though these are specific to hazard mitigation rather than energy efficiency per se. (Institute for Building & Home Safety (IBHS) –)

4. Tenant Satisfaction  Multifamily Retrofits

  • In multiple DOE-sponsored deep retrofit pilots, post-retrofit tenant surveys found:

    • 70–80% of residents reported improved comfort.

    • 50–60% reported noticeable improvement in indoor air quality (less dust, fewer odors, less mold).

    • Over 2/3 said they would be more likely to stay in the building long-term.

    • Deep retrofit residents showed higher reported satisfaction with their units.

  • Residents noted fewer maintenance issues, improved safety, and greater pride in their homes.

  • Turnover rates decreased, which has a measurable financial benefit for property owners.

5. Projected Savings from Compliance

  • Avoidance of Penalties: In jurisdictions like New York City, building owners face fines of $268 per ton of CO₂ equivalent emissions exceeding specified caps. For instance, a building emitting 100 tons over the limit would incur a $26,800 fine annually. Proactively reducing emissions can thus prevent such costs. Or approx. $40k p.a. in fines for a 100 unit building.  GRESB

6. Greenhouse Gas Emissions Reduction

  • Because less energy is used, CO₂ and other GHG emissions drop proportionally.

  • Typical reductions:

    • Multifamily buildings: 25–35% decrease in CO₂ emissions.

    • Aggressive retrofits or net-zero–oriented retrofits: 50–75% reduction.
      (Lawrence Berkeley National Laboratory


7. Water Savings & Waste Reduction

  • Many DER projects also upgrade water fixtures and appliances:

    • Water consumption reductions: 15–30%.

Reduced material use via insulation upgrades and efficient systems also lowers embodied carbon.